Conventionally, cold-rolled steel sheets have been mainly used for automotive body panels. In recent years, however, there has been a strong demand for reducing the weight of automobile bodies, from the viewpoint of improving mileage, and the use of aluminum sheets or plates instead of steel sheet has been studied. Further, aluminum sheets are now actually being utilized for part of automobile bodies. Excellent press formability, high mechanical strength, good corrosion resistance, and the like are required for the aluminum sheets as a material of automotive body panels. An Al—Mg—Si alloy (6000-group alloy), such as 6061-alloy and the like, has been conventionally used as an aluminum alloy for a material to meet such demands as described above.
However, there have been problems that sufficient weldability cannot be obtained by the aforementioned 6000-group alloy, the cost of the aforementioned 6000-group alloy is higher than that of steel sheet, and the like.
An object of the present invention is to provide an aluminum sheet material whose weldability is improved while ensuring mechanical strength and bending property required for a material for automobile body panels.
Another object of the present invention is to provide an aluminum sheet material possessing such characteristics required for a material for automobile body panels, which can be produced at low cost by making use of recycled aluminum materials.